Commercial outdoor lighting fixtures are important not only for the safety and security they provide, but also for their aesthetic contribution to the environment. Such fixtures should blend harmoniously with the landscape while maintaining their utilitarian characteristics. Outdoor lighting fixtures are commonly used in public ways, recreational areas, parking lots, walkways and the like. High-intensity discharge lighting is most commonly used in outdoor applications where a lot of light is required. Among advances in outdoor commercial lighting fixtures are the fixtures disclosed in U.S. Pat. No. 7,097,330 (Outdoor Lighting Fixture); U.S. Pat. No. 6,481,867 (Modular Luminaire Assembly); U.S. Pat. No. 5,918,970 (Outdoor Luminaire Assembly); and U.S. Pat. No. 4,595,971 (Vented Luminaire Fixture).
Despite these and other such advances in the field there remains a need for further improvement in outdoor commercial lighting fixtures, preferably without compromising the advantages previously provided including those related to ease of manufacture, storage, shipment, installation, etc.
Because outdoor commercial fixtures are often large, such fixtures of the prior art suffer from several disadvantages. For example, overheating is a common problem in such lighting fixtures. Among the overheating problems with certain devices of the prior art is a problem of inadequate heat dissipation away from power-related components such as ballasts, lamps and lamp sockets. Certain components, particularly capacitors, ballasts and ignitors, etc., are limited in their ability to tolerate high temperatures. It is critical to the life of certain components, mainly those that are particularly heat-sensitive, that steps be taken to prevent costly damage or, worse, a premature end of the life of the fixture. Overheating can damage power-related components which compromises the longevity of the lighting fixture and its components. Minimal gains in temperature reduction yield very substantial gains in component life and, therefore, in overall fixture longevity.
Commercial outdoor lighting fixtures of the prior art have attempted to solve the substantial problem of overheating. These attempts include, for example, the use of cooling fans, barriers and other insulating features, thermal protection devices, and housings having one or more external power-related components. Each of these attempts to address the concern of overheating have disadvantages and, in some cases, have exacerbated the problem. Additionally, lighting fixtures of the prior art show that certain attempts to contain any overheating have made achieving a pleasing appearance difficult at best. While commercial outdoor lighting fixtures are critical for safety of an area, the appearance of such fixtures has long been sacrificed in the interests of pure utility. As such, there remains a need for such lighting fixtures that can improve the appearance of outdoor environments while still providing necessary safety and security by enhancing visibility.
In addition to overheating concerns, certain fixtures of the prior art sacrifice space within the optics housing by incorporating the power-related components within the same housing. This reduces the space available for the reflector which in turn reduces the performance of the fixture. The larger the reflector, the better the directivity performance and overall efficiency and lighting performance. There is, therefore, a further need for outdoor commercial lighting fixtures having improved efficiency and a pleasing appearance.
The benefits realized in being able to accomplish these two goals—namely improving the overall appearance of such lighting fixtures while reducing overheating of the fixture—would be significant. Accordingly, there remains in the art a need to provide an overhead commercial lighting fixture that more effectively removes heat from the housing, without sacrificing other advantages of benefits realized from earlier development work.